Video security systems are often deployed in and around buildings as well as in metropolitan settings. Example buildings and metropolitan settings include schools, government buildings, commercial buildings, residential buildings, and town and city centers.
These video security systems typically include security cameras that connect via a security network to a control system. Additional components include network video recorder (NVR) systems and monitors for displaying images such as video from the security cameras.
The security cameras typically have a lens and imager system that is fixed, adjustable, or motorized. A fixed security camera will have the lens and imager system permanently fixed in a set position (i.e., lens and imager system cannot change position with respect to camera body). On the other hand, an adjustable security camera's lens and imager system is movable with respect to camera body (e.g., installer can move the lens and imager system to different positions) so that it can be pointed down a hall or at a door, for example. A motorized security camera, such as a pan-tilt-zoom (PTZ) security camera, utilizes motor(s) to automatically move the lens and imager system to different positions usually under operator or automatic control.
An example of the fixed security camera is a fisheye security camera. The fisheye security camera uses an ultra-wide-angle fisheye lens to form an image on the imager chip.
The fisheye security camera is typically used in situations in which there is a need to capture a wide field of view in a single image. The fisheye security camera provides this wide field of view by utilizing the fisheye lens to provide, for example, between 180 degrees and 360 degrees of surveillance range. Due to the wide field of view, the raw image captured by the imager chip is distorted, however.
An example of the adjustable security camera is a dome security camera. The adjustable or dome security camera's lens and imager system includes a lens (e.g., normal lens, wide-angle lens, or long-focus lens) that forms an image on the imager chip. This lens and imager system is adjustable such that it can be positioned in different directions using a gimbal system. Often these gimbal systems enable movement along at least two axes (e.g., two-axis gimbal or three-axis gimbal). The two-axis gimbal provides movement along a roll axis and a tilt axis whereas the three-axis gimbal provides movement along the roll axis, tilt axis, and pan axis. The gimbal allows the adjustable lens and imager system to be moved manually during and after installation to change the fields of view. The adjustable or dome security camera is typically used in locations in which there is a need to capture images from a specific direction.
The installation process of a fixed security camera (e.g., fisheye security camera) for a video security system involves several steps. An installer mounts the fisheye security camera at a desired location that allows for the fisheye security camera to capture a wide area of interest. For example, the fish eye security camera is typically installed directly to a wall or ceiling of a room (i.e., wall mode orientation or ceiling mode orientation) such that the fish eye security camera is positioned to view an entire room. The camera should usually be leveled to ensure good image orientation. Then, the installer will usually program the video security system with the fixed security camera's orientation.
The installation process of the adjustable or dome security camera for the video security system is slightly different. After the adjustable or dome security camera is attached to the wall or ceiling, the lens and imager system is typically positioned to provide either a corridor orientation or landscape orientation with respect to the area of interest. Then, the installer will usually program the video security system with the adjustable or dome security camera's orientation.
In general, there is distortion processing software. Distortion processing software can be used to correct a distorted or warped image by de-warping the image. In particular, this distortion processing software uses image processing algorithms or models corresponding to the lens being used (e.g., fish eye lens) to correct the distorted image.